Diesel and gasoline V-engines utilize intake and exhaust valves to control intake air entering engine cylinders for combustion and exhaust gases exiting the engine cylinders after combustion. The timing of opening and closing of these valves may affect the amount of air available for combustion and the power output and NOx production of the engine. As such, intake and exhaust valve events may be optimized to reduce emissions and improve fuel consumption. However, if valve timing is optimized for high loads, the acceleration performance of the engine at low loads may suffer.
In one example, various hydraulic and electrical variable valve timing mechanisms may provide variable valve timing at different engine operating conditions. However, these systems may require complicated control mechanisms and comprise many components.